This invention relates to a method for the production of fine grain ice or dry clathrate water for manufacture concrete/mortar, a method for the production of concrete/mortar by using fine grain ice or dry clathrate water and concrete/mortar products manufactured by said method. Fine grain ice and dry clathrate water for manufacturing concrete/mortar produced by this invention are used when concrete/mortar is manufactured by the use of a small amount of water.
Thus, concrete/mortar can now be easily manufactured by making use of fine grain ice or dry clathrate water at a place where it is difficult to supply water.
In the case where concrete/mortar is manufactured by a conventional method, much more water is used than the amount of water necessary for hydration of cement in order to uniformly mix and temper cement and water and to keep good flowability as well. However, there is an inconvenience in this method in that strength and durability of concrete/mortar after solidification are lower than the concrete/mortar produced by use of the amount of water close to theoretical hydration quantity.
For this reason, the technique to mix cement or cement and aggregate with fine grain ice instead of water has been studied. The features are as follows:
1) Since powder mixture can be performed with cement, mixing can be performed in low water cement ratio. PA1 2) Loss in slump in proportion to the passage of time is small after mixing. PA1 3) The control of temperature for mass concrete can be easily performed. PA1 1) In the case where a large amount of fine grain ice is fed, a big plant equipped with special devices such as an ice crusher and a slicer is necessary. PA1 2) Fine grain ice must be kept at low temperature until it is used and an ice storage unit is necessary to do so. Therefore, the control of the manufacturing process is troublesome and the cost is high. PA1 1) Fine grain ice or dry clathrate water particles having stable particle size can be easily manufactured. PA1 2) It is unnecessary to keep fine grain ice at low temperature until it is used and it can be used as is or by freezing just before mixture. PA1 3) It is unnecessary to manufacture it at a specified place and manufacture can be easily performed at an optional place in the available time. PA1 4) The method can be easily applied to an existing ready-mixed concrete plant. PA1 5) Water can be transported as fine particles to a PA1 1) Low water cement ratio of high strength concrete/mortar can be easily manufactured. PA1 2) Continuous production is easy to achieve by extrusion molding and roller molding. And, products can be easily enlarged in length. PA1 3) Since water absorbent polymer is mixed in with the cement, a remarkable effect is observed in the prevention of surface dew condensation and efflorescence.
In the case where this concrete mixing technique is actually applied, however, it is necessary to manufacture fine grain ice and this method presents a problem. In a conventional method, fine grain ice is obtained by crushing square ice. In the case where fine grain ice is obtained by crushing square ice, the defects are as follows: